1. Field of the Invention
The present invention relates to a method of fabricating semiconductor packages and to a method of mounting semiconductor device and to a semiconductor device mounting apparatus; i.e., to a method of packaging flip chips, to a method of mounting flip chips or semiconductor devices similar to flip chips by pressure welding toward a connection terminal on a circuit board, and to a semiconductor device mounting apparatus.
2. Description of the Related Art
Packaging apparatuses for mounting IC elements (IC elements or IC devices) on predetermined circuit boards are widely used in miniaturizing circuit systems of electronic devices. For such packaging apparatuses, a pressure welding method is applied to electrically connect flip chips, including IC elements, to a circuit board, as illustrated in FIG. 1 and FIG. 2. Firstly, a predetermined circuit board 2 is fixed by suction to a stage 1 shown in FIG. 1. At the same time, a bare chip 4, fixed by suction to a pick-up head 3, is aligned with stage 1.
In FIG. 1, 1a indicates a vacuum suction system of a stage 1, 3a indicates a vacuum suction system of a pick-up of a head 3, 1b indicates a heating device mounted on a stage 1, and 3b indicates a heating device mounted on the pick-up head 3. The stage 1 and the pick-up head 3 are movable along the X, Y, and Z axes, as well as around the rotational axis. Such mobility enables easy transfer-alignment of the flip chip 4.
Secondly, as illustrated in FIG. 2, the bare chip 4 mounted on the pick-up head 3 is aligned with the circuit board 2 which is fixed by suction to the stage 1. While clamping the bare chip 4 to the pick-up head 3, sealing resin 5 is provided to finally attach the aligned bare chip 4 to the circuit board 2. The heating devices, 1b and 3b, heat the stage 1 and the pick-up head 3 to cure the sealing resin 5. This process is strong enough to weld the protruding electrode 4a of a bare chip 4 to the surface of the circuit board 2. The heating temperature and time are designed to ensure sufficient heat curing of the said shield resin 5.
Thus, conventional methods of mounting bare chips use unitarily packaging apparatuses having functions such as alignment, clamping, and heat curing of sealing resin. Thus, one single packaging apparatus covers all the processes including transfer alignment of the bare chip 4 to the circuit board 2, clamping the aligned and mounted bare chip, and provision and curing of sealing resin 5. This kind of apparatus cures the sealing resin 5 using its own heating devices 1b and 3b while clamping the bare chip 4 to the circuit board 2. The heat curing process takes time, which decreases the efficiency of packaging and the productivity (or availability factor) of the semiconductor device mounting apparatus. One bare chip 4 must always occupy the whole system, including the alignment and pressuring devices, for a fixed amount of time until the sealing resin 5 is heat cured. Thus, other bare chips cannot be mounted until the heat curing process is finished, which decreases productivity and increases manufacturing costs.
Accordingly, it is an object of the present invention to provide a method of fabricating a semiconductor package at low cost.
It is another object of the present invention to provide a method of fabricating a semiconductor package with high reliability.
It is another object of the present invention to provide a method of fabricating a semiconductor package with good yield.
It is another object of the present invention to provide a method of mounting a semiconductor device for fabricating a semiconductor package at low cost.
It is another object of the present invention to provide a method of mounting a semiconductor device for fabricating a semiconductor package with high reliability.
It is another object of the present invention to provide a method of mounting a semiconductor device for fabricating a semiconductor package with good yield.
It is another object of the present invention to provide a semiconductor device mounting apparatus which enables a semiconductor package to be fabricated at low cost.
It is another object of the present invention to provide a semiconductor device mounting apparatus which enables a semiconductor package to be fabricated with high reliability.
It is another object of the present invention to provide a semiconductor device mounting apparatus which enables a semiconductor package to be fabricated with good yield.